function feibo(){
    var n = document.getElementById('feibo_n').value;

    var feiboArray = [];
    if(n<2 && n>0){
        feiboArray[0] = 1;
        feiboArray[1] = 1;
    }
    else{
        feiboArray[0] = 1;
        feiboArray[1] = 1;
        for(var i = 2; i<n; i++){
            feiboArray[i] = feiboArray[i-1] + feiboArray[i-2];
        }
    }

    alert('Feibonacci Array:' + feiboArray.join(', '));

}

function factorial(){
    var n = document.getElementById("fac_n").value;

    var result_number = 1;
    for(var i = n; i>0; i--){
        result_number *= i;
    }

    alert('The factorial result:' + result_number);
}

function hoursTodays(){
    var n = document.getElementById('hours').value;

    var days = parseInt(n/24);

    var lastHour = n%24;

    alert("It's " + days + " and " + lastHour + " hours.");
}

function workOut(){
    var a = document.getElementById('firstNumber').value;
    var b = document.getElementById('secondNumber').value;
    var c = document.getElementById('mathMethod').value
    switch(c){
        case '+':
            
    }
}